Confirming the LHC Higgs Discovery with WW

We investigate the prospects of observing a neutral Higgs boson decaying into a pair of $W$ bosons (one real and the other virtual), followed by the $W$ decays into $qq' \ell\nu$ or $jj\ell\nu$ at the CERN Large Hadron Collider (LHC). Assuming that the missing transverse energy comes solely from the neutrino in $W$ decay, we can reconstruct the $W$ masses and then the Higgs mass. At the LHC with a center of mass energy ($\sqrt{s}$) of 8 TeV and an integrated luminosity ($L$) of 25 fb$^{-1}$, we can potentially establish a $6\sigma$ signal. A $5\sigma$ discovery of $H \to WW^* \to jj\ell\nu$ for $\sqrt{s} = 14$ TeV can be achieved with $L =$ 6 fb$^{-1}$. The discovery of $H \to WW$ implies that the recently discovered new boson is a CP-even scalar if its spin is zero. In addition, this channel will provide a good opportunity to study the $HWW$ coupling

Higgs Boson Interference in γγ→W+W−\gamma \gamma \rightarrow W^+W^-

We study interference effects between resonant and nonresonant amplitudes for the $\gamma \gamma \rightarrow W^+ W^-$ process at a backscattered photon-photon collider. We show that a Higgs boson with $M_H$ > 200 GeV is manifest as a resonant dip in the $W^+W^-$ invariant mass spectrum and we investigate its statistical significance.Comment: 8 pages (LaTeX) + 5 PostScript figures in accompanying file (uuencoded), figures also available by fax upon request to [email protected], UCLA/TEP/93/3

Gluon fusion contribution to W+W- + jet production

We describe the computation of the $gg \to W^+W^-g$ process that contributes to the production of two $W$-bosons and a jet at the CERN Large Hadron Collider (LHC). While formally of next-to-next-to-leading order (NNLO) in QCD, this process can be evaluated separately from the bulk of NNLO QCD corrections because it is finite and gauge-invariant. It is also enhanced by the large gluon flux and by selection cuts employed in the Higgs boson searches in the decay channel $H \to W^+W^-$, as was first pointed out by Binoth {\it et al.} in the context of $gg \to W^+W^-$ production. For cuts employed by the ATLAS collaboration, we find that the gluon fusion contribution to $pp \to W^+W^-j$ enhances the background by about ten percent and can lead to moderate distortions of kinematic distributions which are instrumental for the ongoing Higgs boson searches at the LHC. We also release a public code to compute the NLO QCD corrections to this process, in the form of an add-on to the package {\tt MCFM}.Comment: 13 pages, 4 figures, 3 table

Discovering the Higgs Bosons of Minimal Supersymmetry with Tau Leptons and a Bottom Quark

We investigate the prospects for the discovery at the CERN Large Hadron Collider or at the Fermilab Tevatron of neutral Higgs bosons through the channel where the Higgs are produced together with a single bottom quark and the Higgs decays into a pair of tau leptons, $bg \to b\phi^0 \to b\tau^+\tau^-, \phi^0 = h^0, H^0, A^0$. We work within the framework of the minimal supersymmetric model. The dominant physics background from the production of $b\tau^+\tau^-$, $j\tau^+\tau^-$ ($j = g, u, d, s, c$), $b\bar{b}W^+W^-$, $W+2j$ and $Wbj$ is calculated with realistic acceptance cuts and efficiencies. Promising results are found for the CP-odd pseudoscalar ($A^0$) and the heavier CP-even scalar ($H^0$) Higgs bosons with masses up to one TeV.Comment: 14 pages, 7 figure

Single Charged Higgs production as a probe of CP violation at a Muon Collider

We consider single charged Higgs ($H^{\pm}$) production in association with a $W^{\pm}$ boson at $\mu^+\mu^-$ colliders, in the context of the general CP violating Two Higgs Doublet Model (2HDM). We find that large cross-sections for the processes $\mu^+\mu^-\to H^+W^-,H^-W^+$ are possible, and offer an attractive way of producing $H^{\pm}$ at $\mu^+\mu^-$ colliders. The difference in the cross-sections for $H^+W^-$ and $H^-W^+$ may exceed 1000 fb, and this represents a novel way of probing CP violation in the Higgs sector.Comment: 15 pages, LaTex, 6 figure

Searching for the Higgs Bosons of Minimal Supersymmetry with Muon Pairs and Bottom Quarks

The prospects for the discovery of neutral Higgs bosons (phi^0 = H^0, h^0, A^0) produced with bottom quarks via Higgs decays into muon pairs (pp --> b b-bar phi^0 --> b b-bar mu mu-bar +X) at the CERN LHC are investigated in the minimal supersymmetric model. The complete physics background from the production of b b-bar mu mu-bar, b b-bar W^+ W^- (including t t-bar) and jj mu mu-bar, j = g, u, d, s, c in the Standard Model is calculated with realistic acceptance cuts. This discovery mode has a simple production mechanism from gg --> b b-bar phi^0 with its cross section proportional to 1/cos^2(beta) and could provide an opportunity to measure tan(beta) and the b b-bar phi^0 couplings. In addition, we compare the associated discovery mode above with the inclusive discovery channel pp --> phi^0 --> mu mu-bar +X. Promising results are found for the CP-odd pseudoscalar (A^0) and the heavier CP-even scalar (H^0) Higgs bosons for tan(beta) equivalent to v_2/v_1 >~ 14 and m_A,m_H <~ 325 GeV.Comment: 12 pages, REVTeX, 4 Figure